In 2014 Kalachi, a rural locality in Kazakhstan, reported that more than a fifth of their population were affected by sleep syndrome and that over half of the population of the village planned to move elsewhere. The villagers would fall asleep suddenly even while walking, with some sleeping for over six days. They would wake up groggy with headache and memory loss. It affected young and old alike. Now the cause has been attributed to the nearby uranium mines. A concentration of carbon monoxide reduced the oxygen in the air and led to this sleeping sickness. The villages were evacuated and villagers relocated.
Kalachi Village
